Build, Access, Modify and Delete Fedora objects with the Tuque interface

Using the Tuque API to build and manipulate Fedora Repository objects.¶ ↑

It is inadvisable to rely on functionality available in lower level API objects due to the possibility of these interfaces not being present on all repository implementations in the future.

Connecting to a Fedora Repository¶ ↑

To connect directly to a Fedora Repository using the tuque library:¶ ↑

$connection = new RepositoryConnection($fedoraUrl, $username, $password);
$connection->reuseConnection = TRUE;
$repository = new FedoraRepository(
       new FedoraApi($connection),
       new SimpleCache());

The IslandoraTuque class provides a simple constructor for Islandora users.¶ ↑

D6 module_load_include('inc', 'fedora_repository', 'api/tuque');

No module_load_include is required for Drupal 7 installations.
The IslandoraTuque class is found in includes/tuque.inc and is automatically loaded by the islandora.info file

$my_islandora_tuque = new IslandoraTuque();
$repository = $my_islandora_tuque->repository;

All interaction with Fedora can now take place through the $repository object. D7 There are some wrapper functions that handle some errors and fire some hooks in islandora.module.

To build a new object:¶ ↑

Create array of ContentModels for the object. This will normally be a single element array:

$content_models = array(array('pid' => 'islandora:collectionCModel'));

Identify the namespace for the new pid, and identify the collection the object is to be a member of. Tuque will retrieve the next available PID in that namespace.¶ ↑

$namespace = 'test';
$collection_pid = 'islandora:root';

Create the object directly with tuque:¶ ↑

$fedora_object = $repository->constructObject($namespace); // allow fedora to generate a PID

or with a specified PID:

$fedora_object = $repository->constructObject($pid); // create an object with the given PID

Set the content model¶ ↑

$fedora_object->models = array('islandora:collectionCModel');

Label the object¶ ↑

$fedora_object->label = “my new object”;

Set the owner¶ ↑

$fedora_object->owner = $username;

Build datastream¶ ↑

$datastream_id = “TN”;
$new_datastream = $fedora_object->constructDatastream($datastream_id);

or

$datastream_id = "MODS";
$controlGroup = "X";
$new_datastream = $fedora_object->constructDatastream($datastream_id, $controlGroup);

Set label, mimetype, and content as a minimum. Content may come from url, string, or file¶ ↑

$new_datastream->label = 'MYDSID';
$new_datastream->mimetype = 'something/something';
$new_datastream->setContentFromUrl(URL_TO_CONTENT);

or

$new_datastream->setContentFromFile(PATH_TO_CONTENT);

or

$new_datastream->setContentFromString(“content”);

For datastreams of the Redirect control group:¶ ↑

$new_datastream->url = 'some redirect URL';

Add datastream to object¶ ↑

$fedora_object->ingestDatastream($new_datastream);

Manipulate object’s RELS-EXT¶ ↑

$fedora_object->relationships->remove(FEDORA_MODEL_URI, 'hasModel', 'islandora:collectionCModel');
$fedora_object->relationships->add(FEDORA_MODEL_URI, 'hasModel', 'islandora:imageCModel');

Manipulate object’s RELS-INT¶ ↑

$fedora_object['your dsid']->relationships->remove(ISLANDORA_SCHOLAR_EMBARGO_RELS_URI, 'embargo-until');
$fedora_object['your dsid']->relationships->add(ISLANDORA_SCHOLAR_EMBARGO_RELS_URI, 'embargo-until', 'some date', RELS_TYPE_DATETIME);

Ingest object into fedora repository ¶ ↑

$new_fedora_object = islandora_add_object($fedora_object);

or ingest with existing repository object

$repository->ingestObject($fedora_object);

Working with existing objects. ¶ ↑

Create object to access and manipulate existing Fedora object.¶ ↑

$pid = “test:1”;
$fedora_object = islandora_object_load($pid);

or

$fedora_object = $repository->getObject($pid);

Object evaluates to FALSE if the Object doesn’t exist.¶ ↑

if (!$fedora_object) {
  drupal_set_message("Fedora Object isn't in the repo!");
}

Print the existing models¶ ↑

print_r($fedora_object['models']);

Remove model¶ ↑

unset($fedora_object['models']['islandora:collectionCModel']);

Check if an object has a model¶ ↑

in_array('islandora:collectionCModel', $fedora_object->models);

Purge Object from repository¶ ↑

$fedora_object->repository->purgeObject($pid);

or

$repository->purgeObject($pid);

Delete Object from repository (set object’s state as ‘D’)¶ ↑

$fedora_object->delete()

Get PID of object.¶ ↑

$pid = $fedoraObject->id;

Accessing RELS_EXT¶ ↑

Returns an array of associative arrays representing all relationships.¶ ↑

$rels = $fedora_object->relationships->get()

Each array has two keys, each pointing to its own associative array of values. ¶ ↑

[0] = Array
  (
   [predicate] => Array
       (
           [value] => hasModel
           [alias] => fedora-model
           [namespace] => info:fedora/fedora-system:def/model#
       )

   [object] => Array
       (
           [literal] => 
           [value] => islandora:collectionCModel
       )
  )
[1] => Array......

Returns array of relationships filtered by namespace and predicate¶ ↑

$rels = $fedora_object->relationships->get('info:fedora/fedora-system:def/model#', 'hasModel' );

Datastreams¶ ↑

Get individual datastream by DSID¶ ↑

$datastream = $fedora_object['dsid'];

Get properties of Datastream.¶ ↑

$dsid = $datastream->id;

All datastream properties. Not case sensitive.¶ ↑

label
controlGroup
versionable
state
mimetype
format
size
checksum
checksumType
createdDate
content
url
location
logMessage

Iterate through datastreams in an object.¶ ↑

foreach($fedora_object as $datastream){
 // access individual datastreams.
}

Properties can be accessed or mutated.¶ ↑

$old_mime = $datastream->mimeType;
$datastream->mimeType = “new/mimetype”;
$datastream->content = file_get_contents('http://myexample.com/sample.jpg'));

Creating or updating a datastream that may or may not exist.¶ ↑

// Create DS or grab it.
if (!isset($fedora_object["JP2"])) {
  $jp2_ds = $fedora_object->constructDatastream('JP2', 'M');
}
else {
  $jp2_ds = $fedora_object["JP2"];
}
$jp2_ds->label = 'Derived display JP2.';
$jp2_ds->mimeType = 'image/jp2';
// Don't copy the file.
$jp2_ds->setContentFromFile($jp2_file, FALSE);
// May not need to be called if the DS already existed
$fedora_object->ingestDatastream($jp2_ds);

Exporting an object’s FOXML¶ ↑

See wiki.duraspace.org/display/FEDORA35/REST+API#RESTAPI-export for possible values of the ‘format’, context’, and ‘encoding’ parameters in the call to the Tuque API’s ‘export’ method.

// $foxml is a string containing the requested XML.
$foxml = $repository->api->m->export($pid,
array('format' => 'info:fedora/fedora-system:FOXML-1.1',
  'context' => 'migrate',
  'encoding' => 'UTF-8')
);

Access Resource Index¶ ↑

$objects = $fedora_object->repository->ri->itqlQuery($query, 'unlimited'); // for itql
$objects = $fedora_object->repository->ri->sparqlQuery($query); // for SparQL queries